Motor-controller.



A. J. HORTON.

MOTOR CONTROLLER.

APPLICATION man MAY28,19|4.

1,168,003. Patented 12111.11, 1916.

44 ss 4 .nfllllllllllllll '/l/lllllllllIllll/M/lllllll/l/lill/llllll/111111 UNITED sTATEs PATENT FFUJE.

ALBERT HORTON, 0F WHITE PLAINS, NEW YORK, ASSIGNGE CUTLEB- HAMMER MFG. CO., OIF MILWAUKEE, WISCONSIN, A CORPOBATEON OF WIS- CON SIN MOTOR-CONTROLLER..

Specification of Letters Patent.

Patented J an. 11, 1916.

Application led May 28, 1914. Serial No. 841,610.

To all whom it may concern Be it known that I, ALBERT J. HoRTON, a citizen of the United States, residing at White Plains, in the county of Westchester and State of New York, have invented new and useful Improvements vin Motor-Controllers, of 'which the following is a full, clear, concise, and exact description, reference being had to the'. accompan ing drawing, forming a part of this speci cation.

This invention relates to improvements in motor controllers. l y v The invention, while not limited thereto, is particularly applicable to'dental motors and especially those of the shunt type in which the field takes a relatively large current and the armature a relatively small current. v

The various objects and advantages of the invention will appear from the embodiment thereof illustrated in the accompanying drawing and now to be described,

In the drawing, Figure 1 is a side elevation of the controller; Fig. 2 is a vertical section on line 2 2 of Fig. 1; Fig. 3 is a top plan view of Fig. 2 with the top of the -inclosing casing removed; Fig. 4 is a horizontal sectional view on line 4-4, Fig. 2, but at right angles thereto; Fig. is a sectional `View on line 5 5, Fig. 2,*but at right angles` thereto; and, Fig. 6 is a diagrammatic view showing the controller electrically connected to an-electric motor. v

Referring lirst to Fig. 6, the controller is used to control the direction of operation -and speed of a shunt motor 10. The controller ellects speed` regulationl of the motor through a variable resistance R and more specifically by varying the amount of said resistance included in the armature circuit of the motor. l l

As schematically illustrated the controller comprises a revoluble contact member and a plurality of stationary contact buttons and segments.

13-14, and 15- 16. These pairs of brushes are arranged approximately 120 apart and v6, which constitutes its normal position. 1n

such position the brushes 11 and 12 rest on dead contact buttons 17 and 18, while the The revoluble Contact member f .has three pairs of contact brushes 11--12,

' brushes 13 and 14 rest upon and bridge con.

tact segments 19 and 2O respectively and brushes 15 and 16 rest upon and bridge con tact segments 21 and 22.

The brushes 13 and 15 always remain' in engagement with their respective segments while the brush 14 remains in engagement with its segment 2OI throughout the entire counter-clockwise movementA of the controller and the brush 16 in engagement with its segment 22 throughout thev entire clockwise movement of the controller.- During the counter-clockwise movement of the controller the brush 16 sweeps over a series of contact buttons 23, 24, 25 and'26, while upon clockwise movement of the controller the brush 14 sweeps over a corresponding series of contacts 23a, 24, 25a and 26a. These series of contact buttons are cross connected and are connected to the resistance R whereby movement of the controller in either direction affords regulation of said resistance. Returning to the brushes 11 and 12, the same engage and bridge segments 27. and 28 when the controller is moved in a counter-clockwise direction and engage and bridge segments 29 and 30 when the controller ismoved in aclockwise direction.

The brushes13, 14, 15 and 16, as Iwill hereinafter appear, in addition to regulating the resistance R, control the continuity of the armature circuit of the motor `and also a dynamic braking circuit for the motor armature. The brushes 11 and 12,on the other hand, control the continuity of the field circuit.

The `mechanical embodiment of the controller, as illustrated in the remaining views,

is as follows: rThe aforesaid contacts are all attachment is shownFig. 2" andl as shown l in Fig. 3 the base 34 is similarly supported` at three` points` approximately 1209 apart.

The Contact brushes-are all mounted upon a f circular insulating member 37 arran ed above the base 34 and said member 3 is fixed to a vertical spindle 38 having a bearing 39 in the casing cover and another bearing 40 in the stationary base 3,4. The spindle constitutes the operating medium for the revoluble contact member and has fixed to its upper end a suitable operating lever 41 which, as illustrated, isy of a character common in dental controllers. The lever 41 provides means whereby the revoluble member 37 may be moved in either a clockwise or counter-clockwise direction.

More specifically describing the details of construction, the bearing 40 of the spindle 38 comprises a flanged sleeve set into the base 34 and secured thereto by screws 40a. The revoluble insulating member 37 has' secured thereto, as by rivets 42, a collar 43 surrounding the spindle 38 and fixed thereto by a pin 44. The pin 44 supports the member 37 in a slightly spaced relation with respect to the flange of the bearing 40 to prevent wear between said parts.

The brushes 11 to 16 inclusive, as illustrated in Fig. 2, each comprise a pencil 45 of suitable material sheathed in.,a member 46 reciprocably mounted in the insulating member 37 and placedhunder pressure by a spring 47. The pressure springs 47 of the several brushes are illustrated in Fig. 3 and as shown in this figure, said springs are electrically connected in pairs by cross connectinoP strips 48.

e'ferri-ng to Figs. 2 and 5, means are provided to center the controller in the position indicated in Fig. 6 and to limit the movement of the controller in opposite directions. This means comprises a double-cam member 49 fixed to the lower end of the spindle 38 by a pin 50 and an engaging roller 51 carried by a pivoted arm'52. The arm 52 is pivoted upon a pin 53 projecting downwardly from the supporting base 34 and has associated therewith a spring 54, tensioning the lsame in a direction to press the roller against the cam 49. The spring 54 is connected at one end to said arm and at its opposite end to a second downwardly projectingpin 55 on the base 34. The surface formation of the ycam 49 is such that the pressure of roller 51 thereagainst tends to center the controller while the end formation of the cam 49 is such as to limit the range of movement of the controller.

For admitting the leads to and from the setforth. These resistances, together with the variable resistance R, may, of course, be located as desired. However, as illustrated in Figs. 2 and 5, they may be combined in a single element 58 and mounted within the casing. As shown, theresistance element 58 is supported at opposite ends by bolts 59 and 60 depending from the fixed insulating base 34.

The operation and functions of the controller will now be more specifically described in connection with Fig. 6. Vith the controller in the position illustrated, both the motor armature and .field winding are disconnected from circuit. Vhen the controller is moved in a clockwise direction circuit is established through the motor field winding from line L, by conductor 60 through said winding, by conductor 61 to segment 30 through brushes 12 and 11 to segment 29, by conductors 62 and 63 through resistance R2, yzconductor 64 through all of the resistance by conductor 65 through resistance R to line L2. Also, the armature circuit is completed from line L by conductor 66 to segment 22, thence through brushes 16 and 15 to segment 21, by conductor 67 through the motor armature, by conductor 68 to segment 19 through brushes 13 and 14 to contact 23u through resistance R, by conductor 65 and resistance R to line L2. Thus the motor armature and field winding are connected in parallel between line L and resistance R so that both resistances R and R are common to armature and field branches of the motor circuit. Also, it will be observed that the resistance R2 is included in the field branch of the motor circuit and as will be understood, this resistance is provided to give the desired relative drops in voltage across the motor armature and field. After the motor has thus been started the movement of the controller may be continued whereupony the brushes 13 and 14 will gradually exclude theresistance R from the armature circuit `but leaving the full amount of said resistance in the field circuit. This provides for acceleration of the motor to the desired speed and likewise a reduction in the speed 0f the motor by reverse movement of the controller. The resistance R is fixed and always remains in circuit with both the armature and field branches of the motor. When the controller is returned to the position illustrated the motor is disconnected from' the supply circuit and a dynamic braking circuit is established across the terminals of the motor armature. This circuit extends from the upper terminal of the motor armature by conductor 68 to segment 19 across brushes 13 and 14 to segment 20, by conductor 66 -to segment 22 and across brushes 16 and 15- to segment 21, and thence by conductor l67 to the lower terminal of the motor armature. Accordingly whenI the end and an open end, said base and parts supported thereby being insertible through the open end of said easing.

V9. In a motor controller, in Combination, a cylindrical casing having a closed'end and an open end, an insulating base, fixed and movable ycontacts supported thereby, an operating member for said movable contacts and means biasing said operating member to 10 a predetermined position, said base, contacts,

operating member and means constituting a unit insertible und removable through the open end of said easing.

In witness whereof, I have hereunto Subscribed my name in the presence of two wit nesses.

ALBERT J. NORTON. 'tnesses VM. C. TINTERROHL XV. L. GULLY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

